Quantum technology poses both a threat and an opportunity when it comes to network security. The threat is that powerful quantum computers will be able to crack encryption algorithms. But quantum technology is also the basis for quantum key distribution (QKD) — a more powerful alternative to traditional methods of securing network traffic.
Telecompetitor talked recently with Ryan Lafler, president and chief technology officer for Quantum Corridor, which offers what Lafler believes is the first commercial QKD service in the U.S. We discussed how QKD works and why Lafler sees QKD as the first step in bigger plans for quantum networking.
Quantum Corridor’s network connects Chicago with key locations in Indiana. Lafler is hopeful that the network will help support a burgeoning high-tech community in the area.
Quantum entanglement
The secret sauce underlying QKD is quantum entanglement, in which subatomic particles in separate locations are linked with one another. The entanglement can happen over an appropriately designed fiber network, although there is a distance limitation of about 35 to 45 miles.
What’s important about QKD is that it overcomes a flaw inherent in traditional network encryption methods. Traditionally, end users at opposite ends of the connection use the same algorithm-based digital “keys.” The sender’s key converts the data into an unrecognizable form as it traverses the network, thereby preventing eavesdropping. The recipient’s key then decrypts the information.
The problem is that as computers — particularly quantum computers — become more powerful, they can rapidly try different combinations of bits to essentially guess the correct key.
As Lafler put it, “The problem is that you could continue to fire up at that algorithm until you have success, and then when you have success, you have a breach because you gain access to the transmissions by just being a really good guesser or a rapid guesser.”
Guessing is not possible with an entanglement-based this solution because, as Lafler explained, “You have one attempt to create the session. You have an entangled match or you don’t.”
Any attempt to listen in breaks the entanglement, which breaks the connection.
Importantly, the data exchange that QKD is securing goes over separate fiber connections from those used to establish the entanglement. Traditional data communication methods are used for data exchange. Quantum Corridor’s service logically links the two types of connections.
Eventually, developers envision the data itself to be sent using quantum entanglement, at which point there would be no need for QKD.
Quantum Corridor’s offering
It’s worth noting that QKD isn’t the only option for those who want to secure network communications. Post-quantum cryptography works over conventional communications networks but, like QKD, is designed to withstand eavesdropping from powerful computers expected to be operational within eight years.
So, who’s interested in QKD?
Among others, Lafler said, “We have applications in defense. We have applications for drug synthesis. We have applications for climate modeling systems. We have applications for energy companies.”
To use Quantum Corridor’s QKD service, customers need an edge router, coherent optics and Quantum Corridor’s QKD platform.
Moving forward
Importantly, Quantum Corridor and other companies are working hard to enable quantum entanglement to support more than just QKD. Cisco, for example, wants to interconnect quantum computers using the same approach.
The thinking is that if quantum computers are powerful, multiple quantum computers acting as one would be even more powerful.
Updated to clarify how Quantum Corridor’s QKD offering works
